The invention relates to an apparatus for carrying mobile means of inspection in the interior of a tubular body comprising: a first mobile carrier assembly; a second mobile carrier assembly and a bridge for coupling together the two carrier assemblies, which means of inspection are adapted to emit and receive at least one sweeping radiation beam for inspection purposes, and forming part of which means of inspection are a transducer which is arranged to adopt a stationary position in relation to the said carrier assemblies and is adapted to emit and receive the said radiation beam along a longitudinal imaginary axis through the carrier assemblies, and a reflector which is fitted at a predetermined distance from the said transducer and is rotatable in relation to the said longitudinal axis.
Such an apparatus is known from Dutch patent 181302. With such an apparatus ultrasonic sound is sent by the transducer in the direction of the reflector which comprises an inclined reflecting plane with which the radiation beam is sent in the direction of the interior of the tubular body to be inspected. The radiation beam reflected through the tubular body follows the same path but in the opposite direction and is detected by the transducer.
A problem of the known apparatus is that a circular and full detection on the interior of the tubular body is only possible in one recording pass by using at least two apparatuses in accordance with the known state of the art series-linked at a certain distance. Apart from the circumstances that this is a costly solution, it also gives rise to interference and a relative comparison of the measurement results of the series-linked apparatus in accordance with the known state of the art is not simple.